This application is a 371 of PCT/EP03/02286 filed Mar. 6. 2003, claiming priority from DE 102 11 618.0 filed Mar. 15, 2002, the entire contents of each application are incorporated herein by reference.
This invention relates to new hydrocarbon-based oil components which may readily be incorporated in cosmetic and pharmaceutical preparations, show good dermatological compatibility and provide cosmetic formulations with a particularly light feeling on the skin.
Consumers expect cosmetic skin- and hair-care emulsions to satisfy a range of requirements. Apart from the cleaning and skin/hair-care effects which determine the intended application, value is placed on such diverse parameters as very high dermatological compatibility, elegant appearance, optimal sensory impression and stability in storage.
Besides a number of surfactants, preparations used to clean and care for the human skin and hair contain, above all, oil components and water. The oil components/emollients used include, for example, hydrocarbons, ester oils and vegetable and animal oils/fats/waxes. In order to meet stringent commercial requirements in regard to sensory properties and optimal dermatological compatibility, new oil components and emulsifier mixtures are continually being developed and tested. A large number of natural and synthetic oils, for example almond or avocado oil, ester oils, ethers, alkyl carbonates, hydrocarbons and silicone oils, are used in the production of cosmetic or pharmaceutical preparations. A key function of the oil components—besides their care effect which is directly related to lipid layer enhancement of the skin—is to provide the skin of consumers with a non-sticky, almost instantaneous and long-lasting feeling of smoothness and suppleness.
The subjective feeling on the skin can be correlated and objectivized with the physicochemical parameters of the spreading of the oil components on the skin, as illustrated by U. Zeidler in Fette, Seifen, Anstrichmitt. 87, 403 (1985). According to this reference, cosmetic oil components can be classified as low-spreading (below 300 mm2/10 mins.), medium-spreading (around 300 to 1000 mm2/10 mins.) and high-spreading oils (above 1000 mm2/10 mins.). If a high-spreading oil is used as the oil component in a predetermined formulation, the required feeling of smoothness of the skin is achieved very quickly and, where cyclomethicones, for example Dow Corning 245 fluid (Dow Corning Corporation) or Abil B 8839 (Goldschmidt Chemical Corporation), are used, a velvety feeling desirable to the consumer is also obtained. Unfortunately, the experience does not last long because the high volatility of the last-mentioned structures means that the pronounced feeling of smoothness and hence the velvety feel disappear very quickly, leaving the skin with an unpleasant, dull feeling.
The problem addressed by the present invention was to provide improved, high-spreading oil components which would impart an almost instantaneous and relatively long-lasting feeling of smoothness to the skin and which would show good dermatological compatibility. In addition, the new structures would lend themselves to simple and stable incorporation in emulsions and would be hydrolysis-stable in the event of pH variations.